VHF suspended plate transmitter antenna design for DVB‐T and DAB‐T

Abstract

This paper presents the design of stacked suspended plate transmitter antenna for digital video and audio broadcasting. Contrary to conventional dipole structures, we have designed the antenna in VHF band (174–254 MHz) with two plates for wideband matching and design flexibility. Radiating primary plate has been excited by novel wideband modified inverted L‐type probe. Parasitic secondary plate, and vertical wall between primary plate, and ground plane have been used for further matching and beamwidth adjustment. A bandwidth of 42% and gain of 8.5 dBi is obtained at center frequency. Together with equivalent lumped element circuit model of designed antenna and experimental results for S11, gain, and radiation pattern are presented. To the best of authors knowledge this is the first stacked suspended plate antenna achieving a record bandwidth of 42% in VHF band.

Parasitic effects of the metallic towers on the characteristics of the broadcast antennas

“…For the DVB‐T transmission, the broadband antenna in the UHF band have to be designed assuring a return loss (RL) greater than 10 dB, which implies a Voltage‐Wave‐Standing‐Ratio VSWR < 2 in the whole band . Moreover, the gain and half power beam‐width of the antenna should be such that it can give coverage to a particular area.…”

“…Versatile antennas are being developed with wider bandwidth, higher gain and front‐to‐back ratio, large return loss and half power beamwidth to give optimal coverage to a particular region. Recently, many antennas have been reported in the literature, for DVB‐T applications. When DVB‐T or any broadcast antenna is mounted on top of a tower, it is important to see whether properties of the antenna, such as patterns, impedance, return loss, gain and front‐to‐back ratio, are affected by the tower itself.…”